Although there exist a wide variety of water pumping systems for farm irrigation and other purposes, most such systems are complex, expensive, and require electricity or some other form of man-made power for their operation. In many underdeveloped or depressed areas, however, farmers and other persons requiring water for crop irrigation or other purposes cannot afford to install or maintain expensive pumping systems. Moreover, in many contexts, such as relatively small organic farms built to supply produce to local consumers and restaurants, the amount of water needed may not justify a complex pumping system. Furthermore, in remote areas, access to electricity or other man-made power sources may not always be readily available. Accordingly, there exists a need for inexpensive water pumps that are easy to construct and maintain, don't require access to man-made power sources, and can supply water in volumes needed for relatively small farms and other applications with relatively modest water demands.